When removing a hash entry that was in the cell assigned to its hash, we
would clear the first bit in the second maps. If this entry was a
secondary value with the same hash, then this value became unreachable.
This very rarely showed up for two reasons. First, most of the tables
are insert-only and so we never try to remove things from them. Second,
it requires a particular sequence of inserts. It occasionally caused
weak references to be susceptible to use after free.
This cleans up handling of objects that are not reference counted and
makes their interactions with ARC more consistent. We should probably
generalise this somewhat - it currently special cases NSConstantString
and NSGlobalBlock, but it would be nice to have an API for constant
objects.
This has no effect most of the time, but if the runtime is built with
llvm-cov support, then this will cause each test to emit a .profraw
file, which can be merged with:
$ llvm-profdata merge -sparse Test/*.profraw -o libobjc.profdata
This can then be used to generate coverage reports from the test suite
and find code paths that are not currently being tested.
Coverage checking of the test suite showed that objc_disposeClassPair
wasn't tested at all, which then led to discovering that it didn't
unregister the class.
This test was accidentally passing sometimes, with the isa pointer being
set using some bit of memory in inter-object padding. This breaks
horribly with an allocator that packs objects densely.
Methods now include a selector and extended type encoding, rather than a
method name and lgacy type encoding. Older ones are auto-upgraded.
Expose the extended type encoding via a function that JavaScriptCore
expects to exist.
This change set incorporates a number of changes that all needed to
happen together:
* The imp is now the first field of the `objc_method` structure. This
makes it possible to extend the structure without breaking anything
that relies on being able to access the IMP.
* There is no owner in the slot, so we must use other mechanisms for
determining the owner of a method (e.g. whether the same method appears
in the superclass)
* Again, because there is no owner in the slot, we can't use this as a
fast path for finding the C++ construct / destruct methods. These are
now cached in the class structure when they are found.
* The version field is gone from the slot and now we provide a global
version. This is based on the observation that method replacements
are relatively infrequent and the overhead of invalidating all method
caches is cheaper than adding extra state for every (class, method)
pair.
* A number of the runtime functions are simplified because replacing
the IMP in a `Method` now implicitly updates the dtable.
With the old ABI, we generated a copy of every protocol in every
compilation unit that declared it. We now emit protocols only if they
are referenced (and have the linker deduplicate them).
This test was previously failing with the Apple runtime.
Without this fix, we would lose associated objects silently after adding
the 11th. We would also allocate full pages for each object after the
11th because we couldn't find empty slots.
macOS ships with libc++abi, which doesn't provide the hooks required
for interop, so this was causing all of the tests to fail to link in
the Travis macOS test. We're now correctly detecting that it won't
work on macOS and disabling those tests.
correct.
Instance variables are not normally zero-sized, but some are. Examples
include zero-length arrays at the end of a class, and bitfields.
Fixes#30Fixes#31
When we were trying to get or set an ivar on a class that had
no ivars defined, we'd dereference a NULL ivar list while
determining the ownership qualifier.
at the start of the structure, making it easier to change the layout in
the future.
Also clean up the growth of various fields and consolidate some of the
metadata into a pointer to the `struct objc_method`.
Ensure, when we bounce out from the assembly into C and back again, that
the argument values are preserved. Tests 10 integer and 10 floating
point arguments, which should cover all of the argument registers and at
least one stack slot on all supported platforms.
We were not correctly checking that the object being assigned had a
reference count in the object header. We're also now avoiding assigning
small objects to the weak reference table, which is quite important as
they have no destructor.
Fixes#12
the table incorrectly, causing objects inserted at offsets due to hash
collisions to fail to be moved up and then fail to be found later.
Test by Eric Wasylishen!
David Chisnall
David Chisnall
davidchisnall
Dustin Howett
David Chisnall
David Chisnall
David Lobron
Niels Grewe
theraven